KR20180113577A - Energy-absorbing parts and methods of manufacturing energy-absorbing parts - Google Patents

Abstract

An energy-absorbing component (1) for impact energy absorption is proposed which can be flexibly deformed by impact and optionally undergo at least some degree of failure. The energy-absorbing component 1 comprises at least one core structure 10 and at least one auxiliary structure 12. Wherein the one or more core structures (10) are made from a first material that is a polymer reinforced with metal or continuous-filament fibers, and wherein the one or more ancillary structures (12) And is made from a second material which is a polymer material. One or more auxiliary structures preferably include ribs 14,15,16,18 and are connected to one or more core structures 10 so that one or more of the auxiliary structures 12 are connected to one or more core structures 10 connected thereto. .
The present invention also relates to a method of manufacturing this energy-absorbing part (1).

Description

Energy-absorbing parts and methods of manufacturing energy-absorbing parts

The present invention relates to an energy-absorbing component for the absorption of received impact energy, which can be flexibly deformed by impact and optionally undergo at least some degree of failure. The present invention also relates to a method of manufacturing this energy-absorbing component.

Energy-absorbing parts are used, for example, for bumpers in the automotive industry. This is used, for example, when it is desired to dissipate a large amount of kinetic energy from an impact in a controlled manner in order to minimize negative effects on, for example, passengers or important and costly adjacent structures. In the event of a collision, for example, energy is absorbed through controlled breakage and deformation of the part. Since weight reduction is essential from the viewpoint of reducing fuel consumption, it is preferable to manufacture this part with a lighter weight material, for example, plastic. Another requirement, especially for the type of energy-absorbing part used in the bumper, is that the parts exhibit optimized failure behavior. The goal is to absorb more energy while minimizing installation space.

WO2010 / 015711 A1 discloses a structure for absorbing energy from an impact received. This structure can be flexibly deformed by impact and, optionally, undergoes at least some degree of failure. In one embodiment, the structure has reinforcing ribs, which are arranged at an angle to each other in the axial direction so that the force acting on the structure as soon as one rib is broken is absorbed by the other ribs in the axial direction. The ribs can be made of polymeric materials reinforced with long fibers. This structure exhibits uniform energy absorption.

The manner in which the force introduced into the energy-absorbing part acts on the part is usually non-directional and very dynamic. This leads to a load dominated by compressive force. Thus, the energy-absorbing part should be designed, for example, to avoid buckling risk, i.e. mechanical instability, of the entire part. The result of early buckling is that the actual physical principles used for energy absorption (plasticization, fracture, fiber breakage) do not work as intended, and the energy-absorbing parts do not work in the intended way. In addition to the buckling hazard, another important factor is that the energy-absorbing part has a sufficiently high rigidity with respect to the direction of the force. For example, if a highly effective energy-absorbing component is subjected to a lateral force from a diagonal impact when the force only acts in the axial direction, the result may be desired later due to lateral displacement of the part of the energy- absorbing component or even lateral deflection of the entire energy- Energy absorption can not be maintained.

The geometry of known energy-absorbing parts with thermoplastic or thermosetting matrices reinforced with continuous-filament fibers is very simple due to the manufacturing process. Known absorbers are multi-part absorbers made by joining simple tubes or cylinders, or individually curved planar open profiles, and also simple profiles. As the molding required for a particular force-displacement (energy) feature becomes more complex, the design becomes more complex and more complex. For example, continuous-filament fibers and matrix materials are used to first create customized prepregs before being processed to provide the structure at a later, additional step. Since the fabrication process greatly restricts the geometry of energy-absorbing parts, it is impossible or very limited to integrate functional elements such as fastening systems and threads for secure fastening of the energy-absorbing part itself and for other adjacent structures Do.

The design goal of an energy-absorbing part is a certain amount of energy that must be absorbed over most of the deformation distance. The requirement here is to implement a given force-displacement curve, e.g. as constant a force-displacement curve or ascending in a certain way. An additional condition that is always required is that it is not allowed to exceed a given maximum force in order to avoid damage to components located behind the energy-absorbing component in the direction of action of the force. Where the amount of absorbed energy assumed in any development and also the assumed maximum force depends on the available information about the behavior of the rest of the system at that time. These requirements are often changed during development or when initial testing by prototypes of the entire system is imminent. Here, it is known to use known design principles for scaling previously developed energy-absorbing parts, i. E. Adapting the energy-absorbing parts to altered conditions on the force-displacement characteristics with the maximum allowable force or amount of energy It is often difficult. Thus, there is a need for an energy-absorbing part that can be readily adapted to a given force-displacement characteristic.

Another object of the present invention is to provide an energy-absorbing part that also ensures controlled energy absorption when the lateral force is introduced laterally.

Another object of the present invention is to provide a method which enables easy adaptation of parts to provide a certain force-displacement characteristic in the production of energy-absorbing parts, and which also facilitates easy adaptation of the geometry of parts.

An energy-absorbing part is proposed for the absorption of the received impact energy, which can be flexibly deformed by impact and optionally undergo at least some degree of failure. The energy-absorbing component comprises at least one core structure and at least one auxiliary structure. Wherein the one or more core structures are made from a first material that is a polymer reinforced with metal or continuous-filament fibers, the one or more auxiliary structures comprise a second material, which is a polymer material reinforced with an unreinforced polymeric material, Lt; / RTI > The at least one auxiliary structure preferably includes a rib and the at least one auxiliary structure is connected to one or more core structures. The configuration of the structure and the design of the connection are preferably such that the one or more auxiliary structures support one or more core structures connected thereto.

In the energy-absorbing component, it is preferred that most of the energy generated upon impact is absorbed through the core structure. Wherein one or more auxiliary structures coupled to the one or more core structures support the core structure in a manner that prevents buckling of the core structure when a lateral force is generated from non-frontal impact. In particular, this prevents lateral stripping of the core structure. It is preferable that the design of the core structure is adapted to absorb most of the required energy. Here, the energy absorbed through the destruction of the core structure may be greater than in the case of prior art energy-absorbing components reinforced with continuous-filament fibers, since one or more auxiliary structures coupled to one or more core structures Because it increases resistance. Thus, the energy-absorbing part proposed in the present invention also achieves the intended force-displacement characteristic during the absorption of energy, even when the impact is not exactly frontal and includes lateral components or lateral components.

Another advantageous embodiment provides that energy is primarily absorbed through one or more ancillary structures, in which the design of the core structure is such as to support the ancillary structure. This is achieved, for example, by designing one or more core structures such that one or more core structures surround one or more auxiliary structures.

The energy-absorbing properties of the part, i. E. In particular the force-displacement properties, are preferably adjusted by varying the core structure and by varying the number of core structures used. Here, the expression force-displacement characteristic refers to the force required to deform or break an energy-absorbing part according to the displacement distance, where the displacement distance is a reduction in the direction of the force of the part dimension resulting from the gradual destruction of the part.

Changes in the core structure can be achieved, in particular, by changing the geometry and / or by changing the material used.

The shape of the core structure can be, for example, tubular or conical. This type of geometry can be achieved, for example, by processing the semi-finished product in sheet form into a molding process, or the core structure can be produced directly into this shape.

In particular, when the core structure is manufactured from a planar semi-finished product, it is preferred that the core structure in the planar section perpendicular to the axial direction be a wavy, zigzag or Ω shaped, or linear and / or curved section. Particularly, a shape which can be produced from a planar semi-finished product by a draping process without including an undercut is preferable.

For purposes of the present invention, the expression axial refers to the principal direction of impact acting on the part in the case of an unmodified energy-absorbing part. This direction is also generally equal to the direction in which the length of the energy-absorbing part is maximized.

It is preferred that the core structure in the planar section perpendicular to the axial direction comprises at least one corner. Where the term corner refers to a curvature having a radius of curvature that is on the order of magnitude of the minimum achievable by the material of the core structure through the molding process. These corners provide great stability to the core structure and act as an initial point at which energy is absorbed through controlled destruction of the core structure.

If the energy-absorbing part has a hollow shape, such as a tubular or hollow cone formation, or if the energy-absorbing part is manufactured from a planar semi-finished sheet by a draping process, the wall thickness of the core structure may be adjusted by adjusting the force- Is another parameter that can be changed for. It is preferred here that the wall thickness of the core structure increases or decreases in the axial direction. Thus, it is advantageously possible to increase the force required for further fracture as the fracture of the energy-absorbing part proceeds.

Preferably, the at least one core structure is made of a polymer material reinforced with continuous-filament fibers. Wherein the energy-absorbing properties of the core structure can be influenced through proper selection of polymer material reinforced with continuous-filament fibers. In particular, it is possible here to define the polymer, the fibers used, the proportion of fibers, and / or the orientation of the fibers. Alternatively, the one or more core structures are made of a metal, such as steel or aluminum.

When the first material is a polymer material reinforced with continuous-filament fibers, the proportion of fibers is preferably in the range of 1 to 70% by volume, in particular in the range of 10 to 60% by volume, very particularly preferably in the range of 20 to 50% by volume. The continuous-filament fibers of the first material may be introduced into the first material as one or more layers. Wherein the first material may comprise, for example, fibers in the form of a fabric or in the form of parallel-oriented continuous-filament fibers. It is particularly preferred that the fibers are continuous-filament fibers oriented in parallel.

When the fibers take the form of parallel-oriented continuous-filament fibers when introduced into the first material, those known as tapes can be used, for example. The continuous-filament fibers present in these have a parallel orientation and are filled with a polymeric material. When the fibers are introduced in the form of a fabric made of continuous-filament fibers, the fabric comprises continuous-filament fibers oriented in two or more different directions and woven together, for example.

When the fibers are introduced into a plurality of layers, the orientation of the individual layers can be changed relative to each other in such a way that the individual fiber directions are rotated relative to one another. For example, when two layers of tape are used, the angle enclosed between the two different fiber directions may be e.g. 90 [deg.]. For example, if two fabrics overlap each other, it is desirable to rotate the two fabric layers at an angle of 45 [deg.] To each other to provide an angle of 45 [deg.] Between each of the four fabric directions. It is desirable to place the layers symmetrically through the thickness of the material.

It is preferred that the ratio of fibers in the first material of the at least one core structure is changed in the axial direction. For this purpose, for example, the proportion of fibers in the first material may increase or decrease in the axial direction. This results in a result similar to the result of changing the wall thickness, and the energy required for the destruction of the core structure increases or decreases as the displacement distance increases.

One or more core structures in an energy-absorbing component are bonded to one or more ancillary structures. The bond may be a tight bond, an engaging bond or a friction bond. The close contact can be achieved, for example, by welding or adhesive bonding. In the case of tight bonding, it is also possible to use a casting process such as injection molding, gravity casting, or vacuum casting which casts one or more auxiliary structures into one or more core structures or casts auxiliary structures around one or more core structures. An injection molding process is particularly suitable for this purpose. In the case of meshing defects, it is preferred that connecting elements, for example in the form of latching elements, are formed on one or more core structures and / or on one or more auxiliary structures. Likewise, there may be connection elements, such as, for example, riveted or threaded food elements, provided to couple one or more core structures to one or more ancillary structures.

The one or more auxiliary structures are made of a second material, and preferably have a plurality of ribs.

The second material is, for example, a non-reinforced, i.e., polymeric material that does not include fibers, or a polymeric material that is reinforced with short or long fibers. Here, it is preferable that it is reinforced with short fibers or long fibers. When the second material is fiber reinforced, the proportion of fibers in the second material is preferably in the range of 1 to 70% by volume, particularly preferably in the range of 10 to 60% by volume, very particularly preferably in the range of 20 to 50% by volume.

For purposes of the present invention, the term long fiber refers to fibers generally ranging in length from 5 mm to 25 mm. For purposes of the present invention, the term staple fiber refers to fibers having a length of less than 5 mm, wherein the typical length of the staple fibers ranges from 0.1 mm to 1 mm.

For purposes of the present invention, the expression continuous-filament fiber refers to filaments that are continuously produced and shortened to a defined length during further processing, but whose length is substantially longer than the length of the long fibers. The length of the continuous-filament fibers can be firstly limited through the dimensions of the component, in particular through the dimensions of the core structure. The length can be limited secondly through the dimensions of the semi-finished product manufactured into the core structure through the molding process. It is preferred that the length of the continuous-filament fibers is chosen as large as possible in relation to the part or semi-finished product, so that the length of the fibers corresponds substantially to the dimensions of the core structure or semi-finished product.

The auxiliary structure preferably has a plurality of ribs and includes at least one region molded so that the auxiliary structure can be bonded to one or more core structures. To this end, there is, for example, a portion molded out of the auxiliary structure in a manner that allows for intimate contact of the core structure and the auxiliary structure. The one or more auxiliary structures may also include one or more cavities that are shaped to accommodate the core structure. Alternatively, the outer shape of the ancillary structure may be defined through the shape of the cavity of the core structure, such that the ancillary structure may be received within the core structure.

The ribs of the auxiliary structure are arranged so that the auxiliary structure includes one or more ribs which are connected in axial direction in a first plane and in connection with one or more ribs extending axially in a second plane rotated relative to the first plane . Wherein the auxiliary structure comprises a plurality of ribs parallel to the first or second plane.

In addition to or as an alternative to ribs arranged parallel to the plane extending in the axial direction, it is preferred that the auxiliary structure comprises at least one rib which runs parallel to a plane perpendicular to the axial direction. Here, it is preferable that the ribs parallel to the plane extending in the axial direction intersect the ribs parallel to the plane disposed perpendicularly to the axial direction. Wherein the mutually intersecting ribs preferably form a regular structure of a rectangular shape. Within this rectangle formed by a plurality of ribs, there may be other structures disposed for additional reinforcement. It is preferred here that the further rib divides the rectangle into two halves, and this additional rib connects the two diagonal corners of the rectangle with each other. The orientation of these diagonally extending ribs preferably forms an angle in the range of -45 to +45 relative to the plane disposed perpendicular to the axial direction. This results in two triangular structures. The triangular rib structure is particularly advantageous because it provides a particularly good support effect.

The ribs extending along the axial direction support the one or more core structures such that they are not laterally offset or inverted. Oriented ribs oriented parallel to or parallel to the plane disposed perpendicular to the axial direction in the range of -45 ° to + 45 ° prevent buckling of one or more core structures reinforced with continuous-filament fibers.

The ribs may be more structured, for example, the ribs may have a wavy structure or a zigzag structure.

The auxiliary structure preferably also comprises a functional site, in particular a connecting site. These connection sites serve, for example, to join between one or more auxiliary structures, to secure the energy-absorbing component in its use position, and / or to secure the other component to the energy-absorbing component.

To this end, the one or more auxiliary structures may include a fastening plate on the side remote from the impacted side. Fastening elements, such as perforations, spring action elements, latching elements or threads, which enable the energy-absorbing part to be fastened to its use position, can be arranged on the fastening plate.

It is also possible to place coupling parts in other forms of the auxiliary structure in the form of, for example, an area for a thread element, a dome for a thread element, a spring action element, a latching element and a fastening hole so that other parts can be joined to the energy- It is possible, for example, to fix an auxiliary assembly of a vehicle to an energy-absorbing part when using an energy-absorbing part in a vehicle. As a result, the energy-absorbing part also carries out the maintenance function, saving weight and installation space.

When the first material is a polymeric material reinforced with continuous-filament fibers, the fibers reinforcing the first material are selected from glass fibers, carbon fibers, aramid fibers, varnish fibers, boron fibers, metal fibers, and potassium titanate fibers .

When the second material has fiber reinforcement, the short or long fibers are preferably selected from glass fibers, carbon fibers, aramid fibers, varnish fibers, boron fibers, metal fibers, and potassium titanate fibers. It is also possible to use a combination of the above-mentioned fiber types in the case of continuous-filament fibers or in the case of short fibers or long fibers.

When the first material is a polymer material reinforced with continuous-filament fibers, the polymer of the first material is preferably a thermoplastic polymer or a thermosetting polymer. Suitable thermosetting polymers are, for example, epoxy resins or polyurethane resins. However, it is particularly preferable that the polymer is a thermoplastic polymer. In this case, any thermoplastic polymer is basically suitable. Examples of suitable polymers are polyamides and polypropylenes, but polyamides are particularly preferred. Examples of suitable polyamides are PA 6, PA 66, PA 46, PA 6/10, PA 6T, PA 66T, PA 9T, and also PA 11 and PA 12.

The polymer of the second material is preferably a thermosetting polymer or a thermoplastic polymer processed by a casting process. However, it is particularly preferable that the polymer is a thermoplastic polymer. Any thermoplastic polymer is suitable herein. Examples of suitable polymers are polyamides and polypropylenes, but polyamides are particularly preferred. Examples of suitable polyamides are PA 6, PA 66, PA 46, PA 6/10, PA 6T, PA 66T, PA 9T, and also PA 11 and PA 12.

It is preferred that the polymers selected for the first material and the second material are the same or selected and each polymer is compatible with each other. Both polymers are considered to be compatible if, in the injection molding process, one can create a bond with good adhesion between the materials using a close-bonding process, such as injection or welding of one material onto another.

It is preferred that the energy-absorbing component further comprises one or more inserts. The insert is preferably placed in contact with the core structure, particularly on the side where the impact is applied to the energy-absorbing part. However, it is also possible to introduce the insert into the energy-absorbing component at other locations, for example to provide controlled reinforcement. Wherein the insert is fastened to the one or more ancillary structures. The insert may further comprise coupling means, e. G. Threads, that enable coupling of the auxiliary assembly to the energy-absorbing component, for example. The coupling means can also be used to fasten the energy-absorbing part to its use position.

In the case of an arrangement having an insert on the core structure, it is preferred that the insert is in contact with at least one contact site on the core structure. When an impact is applied to the energy-absorbing component, the contact area where the insert is in contact with the core structure acts like a ram or blade, thus becoming the starting point for controlled destruction of the core structure with energy absorption. Thus, controlled and destructive energy absorption is assured through controlled destruction of the core structure. It is preferred that the insert contact 1 to 10 contact sites on the core structure to provide 1 to 10 start points for controlled failure. It is particularly preferred to use 2 to 8 contact sites per core structure.

The insert is preferably made of metal or plastic. The shape of the insert may be, for example, annular, wherein the ring may have a flattened shape. An annular insert made, for example, of metal, is arranged in the core structure reinforced with continuous filament fibers so that controlled desired delamination, i. E. Interlayer splitting, with the desired fiber break through the axial cracks. This is accomplished by axially pushing or forcing the disclosed insert through the core structure to destroy the structure while dissipating energy. The particular design of the insert allows each of the basic failure modes to be accessed individually and suitably through changes in cross-sectional area or number of cracks, for example accompanied by delamination, so that the above described force- It is possible to improve the possibility of expanding energy-absorption.

The energy-absorbing component preferably comprises a housing comprising at least one core structure and at least one auxiliary structure. The housing may take the form of, for example, a box or a cage, and may be made of metal or polymer, for example. When the housing is made of a polymer, the polymer selected may be, in particular, the same or compatible with the polymer of the first and / or second material. When the energy-absorbing part is used in a vehicle, the housing may be part of the vehicle body structure of the vehicle. The housing may be, for example, a roof frame of the vehicle or a lateral door frame.

The housing of the energy-absorbing component may further reinforce the stability of the one or more core structures and the one or more auxiliary structures contained therein and optionally may be used to fasten the energy- It is possible to provide an additional connecting portion that can be fastened to the part.

It is preferred that the cavity of the energy-absorbing component is filled with foam. Here, the cavity inside the core structure and / or inside the auxiliary structure may be filled with foam. Where the energy-absorbing part further has a housing, suitable perforations or channels may be provided in one or more core structures and / or in one or more auxiliary structures for the introduction of the foam, and the foam inside the housing between the housing and the structure contained therein There may be a cavity filled in. The foam is preferably a polyurethane foam, a polyamide foam or an epoxy thermosetting foam.

The foam first sustains the structures of the energy-absorbing part. Second, the adhesive foam prevents or at least inhibits uncontrolled release of sharp shards upon impact.

The energy-absorbing part shall have a constant force-displacement characteristic according to its intended purpose and be suitable for the absorption of a predetermined amount of energy. Another factor that needs to be taken into account in the design of the part is the fact that the energy of the energy-absorbing part is set so as to avoid damage to the elements arranged behind the energy- It is necessary to avoid excess. Also, in very rare cases, it is possible to consider separate energy-absorbing components, since it is necessary to interact with other components at a given location of use. The factors that need to be taken into account in the design of the energy-absorbing part here are the arrangement of the connection part and the external dimension. By dividing the energy-absorbing parts proposed by the present invention into core structures and auxiliary structures, it is advantageously possible to assign various requirements individually to one or more core structures and one or more auxiliary structures, for example, exclusively one or more By varying the core structure in its nature and / or number, it is possible to achieve an appropriate adaptation to the amount of energy absorbed and also to the force-displacement characteristics, such that the outer dimensions of the energy- Lt; / RTI > Thereby, the performance of the energy-absorbing part can be scaled as needed without changing the arrangement of the connection part of the energy-absorbing part or the external design. For example, when the energy-absorbing parts of the present invention having the same external geometry in different vehicles of mass requiring the introduction of different amounts of energy are used, the force-displacement characteristics may be scaled by simple modification of one or more core structures . For example, wall thickness, fiber / polymer-material combination, layer structure in the longitudinal and thickness direction, reinforcement architecture, and fiber content can be varied without changing the external design of the part. The term reinforcing architecture here refers to the selection of the arrangement of fibers within the core structure.

When the energy-absorbing part is intended to be used, for example, in an automobile, the force-displacement characteristic and the amount of energy that can be absorbed, respectively, are adjusted through different choices of one or more core structures, And fixed points can be used. Likewise, it is possible to alter the design of the energy-absorbing part in the design of the vehicle without any influence on other parts of the vehicle, for example other parts fixed to the energy-absorbing parts.

Another advantage is that the proposed energy-absorbing component can combine the advantages of a continuous energy-absorbing structure of continuous-filament fibers with a good energy-absorbing characteristic and the advantage of a short fiber or long fiber alone structure or a complex geometric structure of a fiber non- will be. Structures reinforced with continuous-filament fibers can be energized by various breaking mechanisms, in particular by the energy required to break the continuous-filament fibers, and also by the energy required for delamination of several layers of material reinforced with continuous filament fibers Can be absorbed. The proposed auxiliary structure has a particularly advantageous effect here because it prevents the buckling or lateral deviation of the structure reinforced with continuous-filament fibers in the event of an impact accompanied by lateral forces. The controlled absorption of energy through defined and controlled failure of the energy-absorbing component can be advantageously further improved by the introduction of the insert. The insert may be disposed on the front side of the core structure in the impact direction to provide a predetermined starting point for destruction of the core structure. Thus, the failure mechanism of the energy-absorbing part is controlled through the introduction of the auxiliary structure and optionally the insert, so as to be able to control the breakage behavior of the part, not only in the case of frontal impact, . Thus, the energy-absorbing part of the present invention achieves the specified energy absorption even when the conditions are not ideal. Here, the fracture behavior in the case of impact is particularly affected by the choice of the number of core structures, the selection of the material of the core structure, the selection of the fiber material of the core structure, the choice of the ratio of fibers in the core structure, / RTI > and / or < / RTI > the number of contacts of the inserts disposed in the core structure.

The energy-absorbing component preferably comprises two or more auxiliary structures connected together. Wherein the auxiliary structure may be joined by a connecting element such as a thread element or a rivet, or by welding or adhesive bonding. The combination of a plurality of auxiliary structures also allows for easy fabrication of the structures with undercuts in the casting process.

A further aspect of the invention is the provision of a method of manufacturing this energy-absorbing part. The features disclosed in the description of the energy-absorbing component are also considered to be disclosed herein for the method, and conversely the features disclosed in the description of the method are also deemed to be disclosed in relation to the energy-absorbing component.

In a proposed method of manufacturing an energy-absorbing component having at least one core structure and at least one auxiliary structure, one or more core structures or one or more semi-finished product sheets are placed in a mold. The mold comprises two or more mold profiles movable in opposite directions, wherein the protrusions and depressions of the mold profile comprise a negative phase of the auxiliary structure. The core structure and, respectively, the semi-finished sheet were made of a first material selected from polymeric materials or metals reinforced with continuous-filament fibers.

In a subsequent step of the method, the mold is closed, wherein any semi-finished product that is inserted when the mold is closed provides a core structure through a molding process. The second material is then injected into the closed mold, where one or more ancillary structures are formed. The second material is a polymeric material that does not include fibers or comprises short fibers or long fibers for reinforcement. After the fabrication of the auxiliary structure, the mold is opened and the resulting parts are taken out.

As in the second variant, when inserting the semi-finished sheet into the mold, it is preferably a thermoplastic laminate reinforced with continuous-filament fibers. It is an organo panel comprising, for example, one or more fabric layers made of continuous-filament fibers, or a laid-scrim consisting of a tape reinforced with non-oriented continuous filament fibers or a polymer matrix pre-impregnated.

For the purpose of the present invention, it is also possible for the semi-finished product to undergo a forming process in advance by a separate process. For example, the semi-finished product or preform to be used may be manufactured in advance at another place, and the resulting core structure may be delayed in the injection mold until the final manufacturing process is carried out.

The semi-finished product to be introduced into the mold is preferably heated before injection and can be subjected to a molding process by a mold to provide a final shape.

It is desirable to insert one or more inserts into the mold before closing the mold. Where the inserts can be arranged so that the arrangement at the front of the core structure is the same, for example in the direction in which the impact is applied to the energy-absorbing component. The insert is preferably made of a metal or a polymer, wherein metal is particularly preferred.

Additionally or alternatively, it is also possible to place one or more inserts after casting the auxiliary structure. To this end, it is desirable to provide the ancillary structure with a connecting structure such as a spring loaded element or a latching element, and / or the insert can be connected to the ancillary structure via a threaded element, a rivet fastening or an adhesive fastening.

After the mold is opened, the molded part can be removed and inserted into the housing. Where the component can be fixedly coupled to the housing by a joining process using, for example, welding, adhesive bonding or riveting. The housing may be open in an area axially located in the energy-absorbing part.

After fabrication of the auxiliary structure, the cavities present in the energy-absorbing component can be filled with foam. Wherein the cavities located between the parts of the core structure and / or the auxiliary structure and optionally present in the housing are also optionally filled. For the introduction of the foam, it is preferred that perforations and / or channels are arranged in the core structure and / or in one or more auxiliary structures. Filling the cavity with the foam can be carried out after removing the part from the mold. Alternatively, the parts of the mold can be replaced prior to detachment from the mold, so that a new cavity can be formed which can later be filled with the foam.

It is desirable to combine a plurality of parts manufactured by the proposed method with one another by a bonding process such as adhesive bonding, welding, riveting or threading to form a larger energy-absorbing part. However, each component itself, including one or more core structures and one or more auxiliary structures, forms a functional energy-absorbing component.

The proposed fabrication method enables simultaneous fabrication of a core structure reinforced with continuous-filament fibers and also one or more auxiliary structures. Advantageously, it is possible for one or more core structures and one or more auxiliary structures to be tightly coupled together at the same time. To this end, the first material of the one or more core structures and the selected polymer of the second material of the one or more auxiliary structures are advantageously the same or compatible so that the one or more auxiliary structures can be molded onto the one or more core structures.

In the proposed method, it is advantageously possible to adjust the force-displacement characteristic, and also the amount of energy that can be absorbed, without modifying the mold as appropriate. This is accomplished by simply adjusting the number of core structures / core structures used in the mold. Similarly, when the semi-finished product is used, it is possible to appropriately adjust the number of the semi-finished products to be installed and also the material of the semi-finished product. Here, advantageously, no complicated mold change or the production of a new mold is required.

Separating the energy-absorbing parts into core structures and auxiliary structures also facilitates the integration of additional functionality into the components. When one or more auxiliary structures are produced, for example, by an injection molding process, it is possible to take advantage of all possibilities provided by injection molding techniques. It is possible to integrate the molding, and the retaining system of the flange, the holes, the threaded inserts, and the spring loaded connectors, as is the case with additional functional integration of, for example, inserts made of metal. Thus, the disclosed invention can first provide access to components that have the energy-absorbing properties required in the event of a collision, and second, other primary or secondary structural functions. For example, the energy-absorbing component disclosed herein may be part of a maintenance system for an integral holder of a vehicle cooling system or part of a reinforcement insert in a vehicle body of a vehicle.

In one particularly preferred embodiment of the present invention, during or after the injection molding process, a separate insert made of metal is incidentally incorporated into the energy-absorbing part. The first function of this integrated insert can be to connect adjacent parts to energy-absorbing parts. These may be in the front region of the vehicle retention system, for example, for the cooling system or other auxiliary assemblies. Due to the insert, the fastening of the energy-absorbing part can also provide special support and reinforcement for power transmission purposes.

The proposed energy-absorbing parts are particularly suitable for use in automobiles. Examples of possible mounting locations in automobiles are under the engine hood, in the area of the lateral door frame, in the door module, or in the interior under the cladding element. Another possibility, along with its use in automobiles, is the use of energy-absorbing parts in packaging technology to protect the products that need packaging.

An example of another application is the static use of energy-absorbing parts in the field of road traffic, for example signs, traffic breakers, lane separators, or furniture constructions of buildings or buildings that require protection. Here, in the case of a vehicle collision, kinetic energy is dissipated in a controlled manner such that the vehicle passenger is exposed only to negligible negative effects.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description.

1 is a perspective view of an energy-absorbing part of the present invention.
Figure 2a illustrates the fabrication of an energy-absorbing component through the installation of a core structure.
Figure 2b illustrates the fabrication of energy-absorbing parts through the installation of semi-finished products.
Figure 3 is a perspective view of an energy-absorbing part having a connecting portion.
Figure 4 is a perspective view of an energy-absorbing part having a housing.
Figure 5 shows the placement of inserts in energy-absorbing parts.
Figure 6 is an illustration of the breakage mechanism of a component reinforced with continuous-filament fibers.
Figures 7a, 7b, and 7c illustrate various profile shapes of the core structure.
Figures 8a and 8b illustrate various embodiments of the insert.

1 is a perspective view of an energy-absorbing component 1 of the present invention having a core structure 10 and an auxiliary structure 12. Fig. There is a tight coupling between the core structure 10 and the auxiliary structure 12. In the illustrated embodiment, the core structure 10 is generally tubular in shape, wherein ribs are disposed on each of the two opposite ends of the tube on the curved outer surface of the tube, 1 < / RTI > The first rib 16 is disposed in a first plane extending in the axial direction. The axial direction is indicated by 2 in Fig.

The auxiliary structure 12 further comprises a plurality of second ribs 14 disposed in parallel to a second plane that also runs in the axial direction. The second plane is rotated with respect to the first plane so that an angle of 90 is included between the first plane and the second plane. The second rib 14 intersects with the first rib 16. A plurality of third ribs 15 are also provided, each of which is disposed parallel to a third plane that extends perpendicularly to the axial direction. Along with the second rib 14 and the third rib 15, the first rib 16 forms an area having the shape of a rectangular parallelepiped, where one of the rectangular parallelepipeds is opened. The ancillary structure 12 with the ribs 14,15 and 16 does not buckle or undergo lateral rupture when the core structure is exposed to forces including not only axial but also lateral components The core structure 10 is supported.

1, a portion of the region having the shape of a rectangular parallelepiped is further divided through diagonal ribs 18, and each region having the shape of a rectangular parallelepiped has a triangular shape . The triangular shape exhibits particularly high rigidity and further reinforces the auxiliary structure 12.

The regions located between the ribs 14, 15, 16, and 18 are preferably filled with foam (not shown in FIG. 1). The structures 10,12 are further supported by the foam. Also, in the event of a collision, uncontrolled deviations of sharp fragments from the structures 10, 12 are prevented or at least restrained.

The auxiliary structure 12 of the energy-absorbing component 1 is preferably produced by an injection molding process. To this end, the ribs 14, 15, 16, and 18 are disposed such that undercuts do not occur with respect to the symmetry plane 20. Therefore, the shape of the auxiliary structure 12 shown in Fig. 1 can be easily manufactured by injection molding. The core structure 10 is not made by injection molding and is a completed core structure 10 or semi-finished product when it is put into a mold as described below with reference to Figures 2a and 2b.

2A and 2B illustrate the fabrication of the energy-absorbing component 1. In Fig. Figures 2a and 2b each show a mold 22 comprising two mold profiles 23. The mold profile 23 includes projections 24 and depressions 25, which provide a negative mold for the auxiliary structure. The mold profile 23 can be moved towards each other to close the mold 22. [

In the embodiment shown in FIG. 2A, the core structure 10 is placed in the mold 22 before the mold 22 is closed. In the illustrated embodiment, the core structure 10 is composed of a first polymer material reinforced with continuous-filament fibers. After the mold 22 is closed, a second polymeric material is injected into the mold 22 to produce the auxiliary structure. Wherein the polymer of the first polymer material and the polymer of the second polymer material are selected to be the same or compatible with each other so that a tight bond is formed between the obtained auxiliary structure and the core structure 10. [ After fabrication of the auxiliary structure, the mold 22 is reopened and the formed energy-absorbing parts are separated. Alternatively, it is also possible to produce the core structure 10 with metal and inject the auxiliary structure 12 around it. In this case, the metal core structure is placed in a suitable mold and a second material is injected around the metal core structure, thereby forming an auxiliary structure around the metal core structure.

2B, the semi-finished product 11 is inserted into the mold 22 instead of the core structure 10. In this example, the semi-finished product was made of a polymer material reinforced with continuous-filament fibers. When a thermoplastic material is selected as the polymer of the first polymer material, the semi-finished product 11 is heated before being placed in the mold 22. [ When thermosetting plastics are used, the plastics have not yet been cured. When the mold 22 is closed, it pressurizes the semi-finished product 11 to provide the core structure 10 through the molding process. After the mold 22 is closed, the second polymeric material is injected again to form the auxiliary structure.

Fig. 3 shows another variant of the energy-absorbing part 1. Fig. 1, the energy-absorbing component 1 includes a core structure 10 and an ancillary structure 12 tightly coupled thereto. The auxiliary structure 12 shown in Fig. 3 further comprises a connecting part 30 which can be used to fix the energy-absorbing part 1 in its use position or to connect it to other parts. To this end, the energy-absorbing part comprises a fastening plate 32 with a perforation 36 in the rear, viewed in the axial direction. Two screw domes 34 are arranged on the upper side of the energy-absorbing component 1. The threaded dome 34 may be used, for example, for securing other components.

Wherein the clamping plate 32 and the threaded dome 34 are both designed as part of the auxiliary structure 12 and are preferably fabricated with the auxiliary structure by injection molding.

Fig. 4 shows an energy-absorbing part 1 comprising a housing 40. Fig. The housing 40 includes a core structure 10 and ancillary structures 12 in intimate contact with the core, as described with respect to FIG. Inside the housing 40, a cavity 42 is left between the housing 40 and the structures 10, 12 contained therein, preferably including a foam (not shown in Fig. 4). The structures 10,12 are embedded within the foam and are connected to the housing 40 by a foam. In a different embodiment, the cavity 42 is completely filled with the foam, or the foam is disposed only in selected portions of the cavity 42.

5 shows the arrangement of the inserts 50 in the core structure 10 of the energy-absorbing component 1. In Fig. In the illustrated example, the insert 50 takes the form of a rectangular frame and is in contact with the core structure 10 reinforced with continuous-filament fibers at four contact sites 52. The insert 50 is in front of the core structure 10 in the axial direction so that the insert 50 is forced into or through the core structure 10 in the event of a collision. At the contact site 52, the insert 50 cuts into the core structure 10 in a knife-like fashion, thus defining the starting points for cracking within the core structure 10. This reliably provides the specified fracture behavior or fracture behavior of the core structure 10.

The insert 50 may be connected, for example, via a coupling element, such as a latching element or a spring loaded element, disposed on the auxiliary structure 12. Examples of other possible connection methods include fixing the insert 50 using threads or rivets, and also using a bonding process such as adhesive bonding or welding. Alternatively or additionally, the insert 50 may be embedded in the foam together with the core structure 10 and the auxiliary structure 12.

Fig. 6 illustrates a failure mechanism of a component reinforced with continuous-filament fibers in connection with panel 60 reinforced with continuous-filament fibers. The continuous-filament fibers 64 take the form of, for example, a fabric, multilayered radscream, or tape. In the illustrated embodiment, multiple layers 62 of continuous-filament fibers 64 are disposed. The action of the force from above breaks the continuous-filament fibers 64 in the two cracks 66. The breakage of the continuous-filament fibers 64 requires a large amount of energy, so that the panel 60 can absorb a large amount of energy. Further, delamination occurs between the individual fiber layers 62, and in the embodiment shown in Fig. 6, several fiber layers are tilted forward and some are tilted backward. Since delamination also requires energy, energy is also absorbed by this second breakage mechanism.

In both cases, the ideal absorption requirement of the impact energy is that the cracks 66 extend downwardly through the panel 60. Lateral deviation of the panel 60 will separate the panel 60 from the forces acting on this panel, without the absorption of energy as intended through cracking and delamination. Thus, the auxiliary structure 12 serves to advantageously support the core structure 10 reinforced with continuous-filament fibers, and even when exposed to forces by the transverse components, the energy-absorbing parts of the present invention are exposed Ensuring that the energy absorbed is absorbed.

Figures 7a, 7b and 7c illustrate three differently shaped core structures 10, for example. Each shape is shown as an axial cross-section.

Figure 7a shows a hollow profile with four corner portions. This core structure can be obtained, for example, from two organo panels connected together. This is achieved by treating the first organo panel with a drape forming process and then bonding it to the second organo panel by close contact, e.g. by welding or adhesive bonding.

Figure 7B shows an OM-shaped core structure. This shape has two corners and an arc therebetween, and can be obtained, for example, by treating the organo panel with a drape forming process. When two of these OMEGA- shaped core structures are arranged to exhibit mirror reflection to each other and are joined, for example by welding or adhesive bonding, as shown in Figures 1, 3, 4 and 5, Is obtained.

Figure 7c shows a core structure with four corners corresponding to the shape of Figure 7a but not closed by engagement with a second organo panel.

In addition to the examples shown in Figs. 7A, 7B and 7C, core structures of other shapes are conceivable. When the core structure is made of metal, it can take the form of a tube or metal profile that is particularly shortened to the required length.

8A and 8B show two examples of the insert 50. Fig.

The insert 50 shown in FIG. 8A takes the form of a flat metal ring.

Fig. 8b shows a triangular shaped insert 50. Fig. The insert 50 of Fig. 8b additionally includes a coupling element in the form of a thread 38, so that the insert 50 provides additional possibilities for the fixation of the other components.

1 Energy-absorbing parts
2-axis direction
10 core structure
11 Semifinished product
12 auxiliary structure
14 Second rib
15 third rib
16 first rib
18 Diagonal ribs
20 Symmetrical plane
22 mold
23 Mold Profile
24 protrusion
25 depression
30 Connection area
32 fastening plate
34 threaded dome
36 boring
38 thread
40 Housing
42 cavity
50 inserts
52 Contact area
60 panels
62 fibrous layer
64 fibers
66 crack

Claims (15)

An energy-absorbing component (1) for absorption of received impact energy, which can be flexibly deformed by impact and optionally undergo at least some degree of destruction, said energy-absorbing component (1) comprising one or more core structures Wherein the at least one core structure is made of a first material that is a polymer reinforced with metal or continuous filament fibers and wherein the at least one auxiliary structure comprises at least one auxiliary structure, Is made from a non-reinforced polymeric material or a second material that is a polymeric material reinforced with short or long fibers,
Wherein the at least one auxiliary structure includes ribs and wherein the at least one auxiliary structure is coupled to the at least one core structure. 2. The method of claim 1, wherein the shape of the core structure (10) is tubular or hollow conical, or the core structure (10) comprises at least one corner in a planar section perpendicular to the axial direction. Absorbing parts (1). 3. A method according to claim 1 or 2, wherein said core structure (10) is of a wavy, zigzag or Ω type, or linear and / or curvilinear section as viewed in planar section perpendicular to the axial direction Energy-absorbing parts (1). 4. Energy-absorbing component (1) according to any one of claims 1 to 3, wherein the wall thickness of the at least one core structure (10) increases or decreases in the axial direction. A method according to any one of claims 1 to 4, wherein the auxiliary structure (12) comprises at least one first rib (16), axially extending in a first plane and extending in the first plane Is connected to at least one second rib (14) extending axially in a second plane rotated relative to the first plane. 6. Energy-absorbing component (1) according to claim 5, wherein the auxiliary structure (12) further comprises at least one third rib (15) arranged perpendicularly to the axial direction. 7. A continuous filament according to any one of claims 1 to 6, wherein the continuous-filament fibers and / or optionally short fibers or long fibers are selected from the group consisting of glass fibers, carbon fibers, aramid fibers, varnish fibers, boron fibers, (1). ≪ / RTI > 8. A method as claimed in any one of the preceding claims, wherein the energy-absorbing part (1) further comprises at least one insert (50), the insert (50) 10 and covers at least a portion of the core structure 10, and / or the insert 50 includes a connection element for connection to other components,
The insert (50) is preferably in contact with the core structure (10) at one to ten contact sites. 9. A method according to any one of claims 1 to 8, wherein the predetermined fracture behavior upon impact is selected by the number of core structures (10), the choice of a first material, the wall thickness of one or more core structures And / or the selection of the number of contact points of the insert (50) arranged on the core structure (10). 10. Energy-absorbing component (1) according to any one of claims 1 to 9, wherein the at least one auxiliary structure (12) comprises at least one connection part (30). 11. Energy-absorbing component (1) according to any one of claims 1 to 10, comprising a housing (40) comprising at least one core structure (10) and at least one auxiliary structure (12). A method of manufacturing an energy-absorbing component (1) according to any one of claims 1 to 11, having at least one core structure (10) and at least one auxiliary structure (12)
comprising the steps of: a) preparing one or more core structures (10) made of a first material or one or more semi-finished sheets (11) made of a first material for the production of a core structure (10) (22), wherein the protrusions (24) and depressions (25) of the mold profile (23) comprise a negative phase of the auxiliary structure (12) Or a polymer material reinforced with continuous-filament fibers,
b) closing the mold 22, wherein, when the mold 22 is closed, any inserted semi-finished product 11 is subjected to a molding process to provide the core structure 10,
c) injecting a second material, which is a fiber-reinforced polymer or a polymer reinforced with short fibers or long fibers, into the mold 22, wherein at least one auxiliary structure 12 is formed,
d) opening the mold 22 and taking out the component 1
≪ / RTI > 13. The method according to claim 12, wherein in step a) one or more inserts (50) are further inserted into the mold (22). The method according to claim 12 or 13, wherein the cavity (42) of the energy-absorbing component (1) is filled with the foam after removing the component (1) from the mold (22). 15. A method according to any one of claims 12 to 14, wherein the force-displacement characteristic of the energy-absorbing part (1) is established through the selection of one or more core structures (10).

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